In a certain code, 'COMPUTER' is written as 'DPNQVUFS'. How is 'LAPTOP' written in that code ?

Analyze the relationship between the letters of 'COMPUTER' and 'DPNQVUFS':
Each letter is shifted to its immediate next alphabetical position ($+1$):
$\text{C}+1=\text{D}$
$\text{O}+1=\text{P}$
$\text{M}+1=\text{N}$
$\text{P}+1=\text{Q}$
$\text{U}+1=\text{V}$
$\text{T}+1=\text{U}$
$\text{E}+1=\text{F}$
$\text{R}+1=\text{S}$

Applying the exact same $+1$ rule to 'LAPTOP':
$\text{L}+1=\text{M}$
$\text{A}+1=\text{B}$
$\text{P}+1=\text{Q}$
$\text{T}+1=\text{U}$
$\text{O}+1=\text{P}$
$\text{P}+1=\text{Q}$

So, 'LAPTOP' is coded as MBQUPQ.